1. Field of the Invention
The present invention relates to an image processing apparatus that generates a driving support image by using a photographed image from a camera (hereinafter, also called a vehicle camera) incorporated in a vehicle, to a driving support system having the image processing apparatus and to an image processing method that generates a driving support image by using a photographed image from the vehicle camera.
2. Description of the Related Art
Together with spreading awareness of safety in recent years, vehicles that incorporate a camera are increasing. It is useful to safety support of drivers that a camera is incorporated in a vehicle and an area around the vehicle which is a blind spot for the naked eye or over a mirror is displayed.
Conventionally, as a display method for displaying an area around a vehicle by using a photographed image from a vehicle camera, a display method is known, in which an image obtained by superimposing a guide (a distance index preset on a road surface) on a photographed image from the vehicle camera is displayed. Because such a display method is easy for a driver to visually understand the distance to an obstacle (e.g., a three-dimensional, that is, 3D object higher than the road surface where the vehicle is present, or a portion lower than the road surface where the vehicle is present) by using a guide, the display method is effective for parking support of a vehicle and the like. Besides, a display method for displaying a guide depending on the height of a 3D object is also proposed. In these display methods, it is easy to understand the distance between a 3D object and the bumper height of the driver's vehicle and the like by depicting guides having a plurality of heights. In addition, as a display method for displaying a link support guide for a trailer, a display method is also proposed, in which a guide is displayed only when a template attached to a target trailer is present in a photographed image from a vehicle camera.
In the conventional display method that displays an image obtained by superimposing a guide on a photographed image from a vehicle camera, because the guide is always displayed, the guide is depicted with overlapped on a 3D object in the photographed image from the vehicle camera (see FIG. 18A and FIG. 18B). A guide line is formed of, for example: an extension line from a right end of a vehicle; an extension line from a left end of the vehicle; a line indicating a position 0.5 meter away from a back end of the vehicle; a line indicating a position 1.0 meter away from the back end of the vehicle; and a line indicating a position 2.0 meters away from the back end of the vehicle. In FIG. 18A, a line (a guide line) indicating the position 1.0 meter away from the back end of the vehicle overlaps a bicycle that is a 3D object; and an extension line from the right end of the vehicle, an extension line from the left end of the vehicle, and a line (a guide line) indicating the position 2.0 meters away from the back end of the vehicle overlap with a fence that is a 3D object. In FIG. 18B, the extension line from the right end of the vehicle, the extension line from the left end of the vehicle, the line indicating the position 1.0 meter away from the back end of the vehicle, and the line (the guide line) indicating the position 2.0 meters away from the back end of the vehicle overlap the fence that is a 3D object. In FIG. 18A, line segments indicated by slanted lines represent white lines depicted on a road surface.
As described above, the guide that is originally a distance index on a road surface is depicted on a proportion that is not the road surface, which is a confusing display for the driver.